• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.6
• /
• pp.733-743
• /
• 2003

The flow field in multiple fluid sphere systems was studied analytically. The expanded zero vorticity cell model based on Kuwabara's theory (1959) was applied and the effects of gas slippage at the collecting surface were considered. Also, the solid sphere system was extended to fluid sphere including the effects of the induced internal circulation inside the liquid droplet spheres or gas bubble systems. As a result, the obtained analytic solution was converged to the existing solutions for flow field around solid and bubble sphere systems with proper boundary conditions. Based on the resolved flow field, the terminal velocity around the collecting fluid spheres was obtained. Subsequently, this study evaluated the most general solution for flow field around the multiple fluid sphere systems. The obtained flow field in multiple fluid sphere could be used as a fundamental consideration of wet scrubber design and devices for removing particles by fluid-fluid interactions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.855-860
• /
• 2006

In this paper, a numerical case study is carried out on the hydroelastic vibration of rectangular plate with various fluid field. It is assumed that the tank wall is clamped along the plate edges. The VMM(Virtual Mass Method) of Nastran is used for the simulation of fluid domain and calculating natural frequency of fluid-coupled structure. In this paper, natural frequencies are calculated and compared for rectangular plates with various fluid field such as infinite fluid and finite fluid, length change of finite fluid field and various fluid contacting conditions.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.1 s.118
• /
• pp.3-9
• /
• 2007

In this paper, a numerical case study is carried out on the hydroelastic vibration of rectangular plate with various fluid field. It is assumed that the tank wall is clamped along the plate edges. The VMM(virtual mass method) of Nastran is used for the simulation of fluid domain and calculating natural frequency of fluid-coupled structure. In this paper, natural frequencies are calculated and compared for rectangular plates with various fluid field such as infinite fluid and finite fluid, length change of finite fluid field and various fluid contacting conditions.

• 한국전산유체공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.144-145
• /
• 2003

A feasibility study on the alternating jet flow under the static electromagnetic field was carried out. When a fluid with electrical conductivity lies in the static electromagnetic field and moves electric current occurs in the fluid. Due to the electromagnetic field and the electric current, lorentz force generates in the fluid, which undergo the 'breaking' effect to the fluid. In order to simulate the complex fluid flow in the magnetic field, electromagnetic and fluid flow analysis need to be solved simultaneously. In the present study, a SOLA (SOLution Algorithm) scheme was used in order to calculate electromagnetic and fluid flow field. Jet flow without an electromagnetic field was compared with analytical solution in order to validate the flow analysis scheme. Effect of jet velocity on the flow pattern down the jet was investigated.

• Journal of applied mathematics & informatics
• /
• v.41 no.2
• /
• pp.401-411
• /
• 2023

The effects of longitudinal velocity dusty fluid flow in a weak magnetic field are investigated in this paper. An external uniform magnetic field parallel to the flow of dusty fluid influences the flow of dusty fluid. Besides that, the problem under investigation is completely defined in terms of identifying parameters such as longitudinal velocity (u), Hartmann number (M), dust particle interactions β, stock resistance γ, Reynolds number (Re) and magnetic Reynolds number (Rm). While using suitable transformations of resemblance, The governing partial differential equations are transformed into a system of ordinary differential equations. The Hankel Transformation is used to solve these equations numerically. The effects of representing parameters on the fluid phase and particle phase velocity flow are investigated in this analysis. The magnitude of the fluid particle is reduced significantly. The result indicates the magnitude of the particle reduced significantly. Although some of our numerical solutions agree with some of the available results in the literature review, other results differs because of the effect of the introduced magnetic field.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.321-324
• /
• 2002

Hydraulic valve control the pressure and the How of fluid by the hydraulic oil transfered from pump but the ER fluid consists of solid particles of micrometer in size and insulating oil so in the general hydraulic valve. We invented ER-Valve using ER fluid as working fluid. The ER fluid, working fluid of ER-Valve is a functional fluid to represent the feature of fluid according to strength of electric field. In this research we made our own 4 types of plate type ER-Valve which has same surface but different width and length and then we conducted performance test. We measured flow rate and pressure drop of fluid which is flowing in the ER-Valve according to the electric field strength to conduct this test. We modeling ER-Valve relating to ER-Valve system and yield shear stress according to the strength of electric field. We used the pressure drop according to the strength of electric field by differential pressure gauge in the our own made ER-Valve. This test reviewed experimental the special changes of ER-Fluid in the steady flow condition.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1994.06b
• /
• pp.19-29
• /
• 1994

Since Winslow (1) has reported an electro - theological (ER) effect which features remarkable and reversible changes in the properties of the fluid due to an imposed external electric field, numerous applications of ER fluids in mechanical devices, such as clutches, control valves, active dampers, and etc. have been proposed to improye dramatical ly their performances (2,3). When the external electric field is imposed to the ER fluid, it behaves as a Bingham fluid, displaying a field dependent yield shear stress which is widely variable. Without the electric field, the ER fluid has a reversible and constant viscosity so that it flows as a Newtonian fluid. Another salient feature of the ER fluid is that the time required for the variation is very short (< 0.001 sec) (4-6). These attractive.characteristics of the ER fluid provide the possibility of the appearance of new engineering technology , for instance, an active vibration control system. Recently, the application of the ER fluid to rotor-bearing systems has been also initiated.

• Tribology and Lubricants
• /
• v.29 no.1
• /
• pp.39-45
• /
• 2013

Magnetorheological (MR) fluid belongs to the group of smart materials. In MR fluid, iron particles in base oil form chains in the direction of the applied magnetic field, thus resulting in a variation in the stiffness and damping characteristics of the fluid. Research is being carried out on controlling the stiffness and damping characteristics as well as the tribological characteristics of the MR fluid. In this study, the friction characteristics of MR fluid have been evaluated using three types of materials and magnetic fields of different strengths. The coefficients of friction of the three types of MR fluid are measured, and the relationship between the coefficient of friction and the strength of the applied magnetic field is obtained.

• Journal of Power System Engineering
• /
• v.8 no.2
• /
• pp.53-58
• /
• 2004

In this paper, the semi active mount featuring Magneto rheological fluid(MR Fluid) is proposed. MR fluid is suspension of micro sized magnetizable particles in a fluid medium, and its apparent viscosity can be varied by the applied strength of magnetic field. When the controllable MR fluid is applied to mechanical devices, the devices provide simple, rapid response interfaces between electronic controls and mechanical systems. The MR fluid is applied in the conventional fluid mount for improving its performance of the mount's isolation effect. A appropriate size of the MR mount is designed and manufactured on the basis of Bingham model of MR fluid. In addition, the field dependent damping forces of MR mount are evaluated with respect to the input frequency variation.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.66-71
• /
• 2001

In this work, an ER clutch has been constructed and its characteristics have been evaluated by adapting an electro-rheological fluid(ERF) as an operating medium. ER fluids are suspensions which show an abrupt increase in rheological properties under electric fields. An ER clutch system using ER fluid is a new conception device because an apparent viscosity of ER fluid can be changed by apply an electric field. As a first, Bingham properties of ER fluids are experimentally distilled as a function of electric field. We use the disk type ER clutch in which the ER fluid fills the annular space between a pair of coaxial disk electrodes and experiment results show that the measured revolution per minute was increased with the increase of the electric field. The ER fluid used in the present study consists of weight fraction 35% in zeolite suspended silicone oil.